SherylM

I also think the problem is probably that her stitch length is too long. In the past year, after watching a Leah Day video and reading several articles on the subject, I started pressing my seams open, and I now prefer to do it that way. But I also started using a much shorter stitch length, and my seams are plenty strong - I can tug on the fabric on either side of the seam and not see daylight.

Perhaps instead of trying to get her to press her seams differently, you could suggest she try shortening her stitch length.